The marina's antenna is a straight shot away and there's no way to reduce the output power on the wirie's alfa unit via the software. Pop some foil over the antenna and my packet loss went from ~50% to 5-10% in a split second. Take it off and the packet loss is back again.

RF in general is black magic; never liked working with it because there are just too many variables.

Rebel where do you have the wirie unit mounted? I looked at these but was afraid I wouldn't be able to get it high enough to be worthwhile. SC

Yep, it's about 70 pages ago that I wrote about reducing power for better connections. Software control over that s crucial and the Ubiquity products do that of course.

The technical reason is that a signal that loud overdrive the receiver at the other end of the link.

ciao!
Nick.

Yup. I usually explain it as two people shouting at each other from 5' away isn't going to be as effective as talking at a moderate voice. San Diego is dense-packed with boats. Sort of ironic that in a worse arrangement my stuff would work better, but a tinfoil sleeve isn't that bad. I'm going to get my wife to sew some into a little canvas "condom" that can slide over the antenna to look a little nicer and not blow off.

Quote:

Originally Posted by sailcruiser

Rebel where do you have the wirie unit mounted? I looked at these but was afraid I wouldn't be able to get it high enough to be worthwhile. SC

Radar post on the stern. It's maybe 8' off the deck and I pick up signals everywhere. It's really a quality product. My friend (a few boats over) has his mounted on his stern life line stanchions and does pretty good as well. He didn't do a permanent mounting job; it's smart to work with it lose and find the best place before you wire it in, if you can.

A friend with a ketch put his on the front of his mizzen and it works great. If you have some dead-obvious spot like that then go for it.

The stern works good too because it juts out just past all the rest of the boats lined up. The less stuff between you and the antenna the better.

Just incase anyone is interested. the reason I'm switching to the bullet system is so I can go wireless. I have a really good Alfa antenna (mentioned earlier in this thread) that I think is great. But the two things I don't like about it is; its directional. I'm currently working with about 4 different open networks, all of which have intermittent quality/strength. So I have to switch networks frequently. I'm much too lazy to go up and move the directional antenna that often... The second thing, and the reason I'm not interested in the wirie, is the USB cable is a pain the arse. I'm constantly ducking under and tripping over it, and I can only use my laptop in one place on the boat.

So after tons of research (basically just reading this thread ) i'm going with the bullet for the freedom!

To make POE is not really a big deal.
Pins 4&5 (the Blue/White pair) are Positive, and Pins 7&8 (the Brown/White pair) are Ground. You're going to need a crimping tool.
The Nanostations and Bullets will all work on 12V. Cheers, Dave

...but a tinfoil sleeve isn't that bad. I'm going to get my wife to sew some into a little canvas "condom" that can slide over the antenna to look a little nicer and not blow off.

If you need to attenuate, are you not probably close enough to receive directly? BTW: All that excess transmit energy has got to go somewhere. Question will be where? With a tin foil sleeve, I'd imaging you're also dramatically affecting receiver sensitivity.

Quote:

Originally Posted by rebel heart

Radar post on the stern. It's maybe 8' off the deck and I pick up signals everywhere. ... My friend (a few boats over) has his mounted on his stern life line stanchions and does pretty good as well. He didn't do a permanent mounting job; it's smart to work with it lose and find the best place before you wire it in, if you can.

A friend with a ketch put his on the front of his mizzen and it works great. If you have some dead-obvious spot like that then go for it.

The stern works good too because it juts out just past all the rest of the boats lined up. The less stuff between you and the antenna the better.

The higher you go the better for both distance and obstruction clearance. They put the VHF antenna at the very top for a reason.

Quote:

Originally Posted by djdeakyne

To make POE is not really a big deal.
Pins 4&5 (the Blue/White pair) are Positive, and Pins 7&8 (the Brown/White pair) are Ground.

The higher you go the better for both distance and obstruction clearance. They put the VHF antenna at the very top for a reason.

HI Michael, Nice How-To on the cable.

I really don't understand all the infatuation with height. The VHF is high for line of sight to the horizon. The "6ft man sees a 6ft man at 6 miles" rule is plenty for the range we're talking about for wifi.

Yes, the antenna does need to be above the bimini and boom, but what is height really buying you. For a hotspot 300 meters away, the top of a 6 degree vertical beamwidth from a high gain omni antenna would still be 15 meters high. Much higher than most bars and coffee shops that I frequent.

I think the real problem is when a narrow beam pitches up and down, above and below the hotspot, the reception will be crappy. Lets face it, 6 degrees is not much for a boat to roll at anchor.

WiFi operates in the UHF frequency spectrum - 2.4 gigahertz and as such is very much "line of sight". From Wikipedia: "The major disadvantage of UHF is its limited broadcast range and reception, often called line-of-sight between the TV station's transmission antenna and customer's reception antenna, as opposed to VHF's very long broadcast range and reception, which is less restricted by line of sight."

So the idea of getting the WiFi antenna up as high as possible/practical is to get it above intervening obstacles like other boats, buildings, etc., etc. Range is not so much the reason for going "high" as getting an obstacle free line of sight between your antenna and the shore stations antenna. Trying to "shoot" through a sea of masts from either anchored boats, moored boats, or other marina boats is frustrating. Moving your antenna half a meter can make a world of difference in the quality of the WiFi you are using.

IMHO, the advantage of the Ubiquiti or other "Cat5/6" cabled systems over USB cabled systems is the problem of hanging the very thin USB cable and active amplifiers and POE equipment 50 or 60 feet up in the air on your mast. The Ethernet exterior rated cables are bigger, stronger and easier to deal with amongst other advantages when putting your antenna system up the mast.There is a very wide range of options for mast mounted WiFi antenna systems be they USB or Ethernet. You can surf around in this website to see what is available: Data Alliance: Alfa WiFi Long-Range Wireless USB Adapters, Antennas, Ubiquiti Access Points

The reason for the VHF being up high is because of the characteristics of that part of the spectrum. That doesn't apply at all for other types of propagation.

The characteristic you are talking about is ground wave line of sight propagation, correct? My handheld VHF at deck level goes about 5 miles (ie "the horizon") It doesn't need to be at the top of the mast to work.

That aside, my point being that wifi is microwave, which is also line of sight, but what are you gaining by putting the antenna at the top of the mast. If you can see the location of the hotspot from the deck of your boat, then you can communicate with it, or am I missing something?

Thanks osiris,
I think I get it, putting it on top of the mast has nothing to do with line of sight for range. It is only to avoid the dark spots created by other masts in the anchorage.

But, unless the hotspot is also elevated, won't the other masts will still be in the way as the line of sight points down to the beachfront bar?

And, how big of a dark spot are we talking about. How bad could a 9" hollow aluminum mast 50 meters away in a swinging anchorage be? 1/4 degree? If the hotspot is being shielded by a mast, it won't be for long the way boats swing around.

Also, we're talking about centimeter wavelengths and most mast thicknesses don't even approach that. Also, my house, or even the coffee shop wifi doesn't seem to have much trouble going through walls that are much thicker than a centimeter. Just wondering.

Hi All,
Thanks for all the great info posted on this thread.
My wifi setup has been working for 4 years now. It is in Revision 2 with the introduction of the Nanostation M2. Here is a video of it in motion.

It provides onboard hotspot and a directional link using Ubiquiti products.
The key for me was to keep the Nanostation pointed at the Access Point. The rotator has a digital compass inside that is used to keep the servo pointing at the same place regardless of how the boat swings.

I currently use Bluetooth to talk to the controller and set the heading.
The only wire going to it is power (+12v,Gnd) Nothing else.

Version 3 will have slip rings so it will have unlimited rotation capability.

Hi! Not sure how this one slipped past me. I have a drawer full of components under my bunk now to make a like device. I can't load your video yet but I am looking forward to viewing it soon. Are you using an Arduino?